The present invention relates to a fixed constant-velocity ball joint of the type described in the preamble of claim 1.
A ball joint having a radial offset has already been proposed. The aim was to avoid any overhang or undercutting of the grooves of the bell at their entry, to facilitate fabrication and assembly of the joint. To achieve this result, the offset must be of the order of 100% of the pitch circle diameter (PCD), which is the distance between the centers of two balls contained in the transverse diametral plane of the joint as measured in said plane and in the aligned position.
In ball joints, in the maximum break position, the ball which is entering the break plane, which is the plane which contains the axes of the two shafts, and outside the break angle, exerts a high force on the groove of the bell, very close to its entry edge. The torque transmission capacity is therefore limited by the risk of this area of the bell collapsing.
The object of the invention is to provide a ball joint in which the aforementioned force is greatly reduced and interaction between the balls and the grooves in the other positions of the balls, and in particular the maximum contact forces, are kept within acceptable limits.
To this end, the invention provides a fixed constant-velocity ball joint of the aforementioned type characterized in that said radial offset is from approximately 15% to approximately 25% of the pitch circle diameter of the joint.
The ball joint according to the invention can have one or more of the features of claims 2 to 5, taken separately or in all technically feasible combinations.
The invention also provides:
an automobile vehicle transmission including at least one ball joint as defined hereinabove; and
an automobile vehicle including at least one such transmission.